·E is the darker of the two films. The Dark Knight spends a lot of time focussing on Joker the chaos-bringer (played compellingly by the late Heath Ledger), suggesting that ‘some men just want to watch the world burn’. Undoubtedly this is true. But The Dark Knight’s fundamental assumption is that while humanity has its sociopaths, and while people must contemplate the ethical dilemmas they face on a daily basis, eventually humanity en masse will make the right calls. This is seen especially in the scene towards the end of the film where the Joker has placed two boatloads of people in a situation where they must destroy the other remotely in order to ensure their own survival. One vessel is full of convicts, the other of civilians. And needless to say, after some forced Ethics 101-style debate, neither craft is destroyed—much to the Joker’s bemusement. If these two groups of people, one ostensibly degenerate and the other nothing extraordinary, can together make a mockery of the Joker’s assumptions about humanity, then this seems to presume humanity’s propensity for making good and right decisions.
Contrast this with Wall·E, where humanity has messed up, literally. The presence of Wall·E himself trundling around a limitless rubbish dump and the existence of infantilised humans floating around in their enormous celestial playpen far, far away testifies to what is surely a statement about an inherently flawed humanity driven by corrupted and poorly formed desires. In The Dark Knight, people—or only certain people, perhaps—merely have the potential to make and act upon immoral decisions; but in Wall·E, humanity has already succumbed to its basest cravings and has thoroughly screwed up in the process.
Both films labour these points more than they need to. As excellent as Ledger’s performance as the Joker is in The Dark Knight, the film’s plot surely makes too much of his character’s frenzied ways to the extent that I cannot help but think that Jerome Valeska (a Joker-styled figure, played by Cameron Monaghan) in Gotham embodies chaos far more effortlessly. In Wall·E, consumerism is the natural target, as is the dulling effects of constant entertainment and ready access to certain sorts of technology. Each film taps into certain fears: The Dark Knight into terrorism and the dangerous unknown or the other more generally, Wall·E into the depths of our daily habits and the effect these have on our lives. And yet Wall·E continues to carry more weight because whereas terrorism and disarray is a continual and very real threat from ‘outside’, consumerism and its handmaids are insidiously, sinisterly pervasive, spreading within each and every one of us whenever we swipe right or upgrade our phones. This is not the fault of technology in and of itself, but technology, if marketed in certain ways, exploits and then reshapes our desires—and this is what leads to humanity’s downfall in Wall·E. Thus Wall·E, I submit, is darker than The Dark Knight.
You can read another article, written in 2009 by Carrisa Smith, on Wall·E and The Dark Knight here.